We could look into it. In the past, we toyed with the idea of doing shout outs on the site. As opposed to live chat, shout outs are similar, but not real time (similar to Twitter now that I think of it). That trend on websites have faded away though because too many people would abuse the feature by posting spam instead of legitimate messages.

As for some sort of chat implementation, it could be a question of compatibility with all visitors (i.e. if it uses Flash or something) and there is the issue of it being unmoderated.